Integrated manifold assembly

ABSTRACT

A manifold assembly for use in conjunction with a servicing apparatus for exchanging fluid between a serviceable automobile component and new and used fluid tanks and including a rigid manifold body with a fluid circuit defining a plurality of pathways connecting a plurality of ports whereby fluid is directed through the fluid circuit and ports by selectively operating first and second valves and circulated using a common pump to exchange fluid, recirculate fluid, and drain both the used and new fluid tanks as desired.

[0001] This application is a continuation-in-part of provisionalapplication No. 60/350,157, entitled Remotely Operated Vehicle FluidExchange System, filed on Oct. 29, 2001, which is hereby incorporated byreference in its entirety.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates to the field of vehiclemaintenance, and more specifically, to servicing automotive fluidcontaining components.

[0004] 2. Background

[0005] Operating fluid reservoirs in vehicles, frequently requireservicing such as replacing used fluid with fresh fluid in order toproperly maintain them and extend the life of the component andassociated vehicle. One such reservoir requiring frequent attention isthe automatic transmission fluid circuit. However, early attempts atdeveloping automatic transmission fluid transfer machines often resultedin relatively lengthy and complicated procedures. Many of these devicesrelied upon compressed gases to circulate the fluid and thus requiredsome sort of compressed air source adding to the device's complexity.Such early attempts also required significant manual operation andsupervision as the operator had to continually monitor gauges and otherinstruments to monitor the fluid flow to achieve the desiredperformance. The devices themselves typically consisted of multiplecomponents such as valves, pumps, and gauges in addition to severallengths of hoses or conduits to provide the requisite plumbing system toconnect the various components within the system and to the vehicle'stransmission.

[0006] While some of these devices proved satisfactory for their time,the next level of automatic transmission fluid transfer machinesintroduced a degree of automation to the fluid exchange process thusreducing the extent of operator intervention. However, the plumbingproposed in an effort to automate the process and perform the stepstypically associated with a complete automatic transmission fluidservice, typically continued to employ a relatively large number ofplumbing components such as multiple dedicated pumps, gauges, andseveral valves. Again, a number of conduits connecting the variousdevices were used as a means of transferring the fluid between eachsource and destination.

[0007] Some examples of these automatic transmission fluid devices canbe found in U.S. Pat. Nos. 5,482,062 and 5,337,708 to Chen; 6,062,275 toRome et al., U.S. Pat. No. 6,035,903 owned by the assignee of thisappication; and Japanese Unexamined Patent Application No. 2-72299. Itis clear from a review of the devices shown in these patents that whilesuccess was achieved in reducing some number of components, the focuswas primarily on automating the process and thus a relatively largernumber of components is still required to carry out of all the desiredfunctions, especially the connections between the various componentswhich require hoses or conduits for conducting fluid between each pointalong the fluid transfer path. In addition, the above devices have notfocused on maintenance of the unit and connection and disconnection inthe field remains more complicated than is necessary.

[0008] Thus, while some of these devices such as that described in U.S.Pat. No. 6,035,903 have proven satisfactory in the field, there remainsthe ever present need to develop a manifold assembly with integratedcomponentry for use in conjunction with a fluid changing apparatus witha minimal number of components and omit or reduce hose lengthrequirements to reduce costs, maintenance, and assembly time, yet stillperform the fluid servicing procedures associated with an automatictransmission service.

SUMMARY OF THE INVENTION

[0009] In accordance with the present invention, a manifold assembly foruse in conjunction with a fluid servicing apparatus including used andnew fluid tanks and a pump generally includes a manifold body defining aplurality of ports and a fluid transfer circuit at least partiallyformed within said body between said ports with selectively operablefirst and second valves for diverting fluid between a first port and asecond port or a used fluid port or diverting fluid from said used fluidport or a new fluid port to said second port. A pump is interposedbetween said fluid ports and said second port for transferring fluidtherebetween. Some of said ports of said manifold body being connectableto said servicing apparatus tanks for transferring fluid between themanifold body and the respective tank.

[0010] Another feature of the present invention disclosed hereinincludes a fluid transfer circuit including a drain path, a bypass path,a supply path, and a dump path and said drain and bypass paths divergewhile said supply and dump paths converge.

[0011] Yet another feature of the present invention is the formation ofthe fluid transfer circuit in said manifold body in adjacent linearsegments.

[0012] In yet another aspect of the present invention, the manifold bodyincludes threaded ports for receipt of at least one filter or valve.

[0013] A method of assembling the manifold assembly with a servicingapparatus is also disclosed herein.

[0014] Other aspects of the present invention will become apparent withfurther reference to the following drawings and specification.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a right front perspective view of a preferred embodimentof the automotive fluid servicing apparatus of the present invention;

[0016]FIG. 2 illustrates an exemplary control panel, in enlarged scale,included in the automotive fluid servicing apparatus shown in FIG. 1;

[0017]FIG. 3 is a right front perspective view, in enlarged scale, of anexemplary manifold incorporated in the automotive fluid servicingapparatus shown in FIG. 1;

[0018]FIG. 4 is a schematic of an exemplary plumbing circuit forwithdrawing used fluid from a power steering reservoir of a vehicle inan alternative embodiment of the automotive fluid servicing apparatus ofthe present invention;

[0019]FIG. 5 is a schematic of an exemplary plumbing circuit for addingnew fluid to a power steering reservoir of a vehicle in an alternativeembodiment of the automotive fluid servicing apparatus of the presentinvention;

[0020]FIG. 6 is a schematic of an exemplary plumbing circuit forperforming servicing procedures in accordance with a preferredembodiment of the automotive fluid servicing apparatus shown in FIG. 1;

[0021]FIG. 7 is a schematic of an alternative plumbing circuit forperforming servicing procedures in accordance with an alternativeembodiment of the automotive fluid servicing apparatus of the presentinvention;

[0022]FIG. 8 is a partial sectional view taken from the plumbing circuitin FIG. 6 illustrating an exemplary recirculation/bypass fluid path;

[0023]FIG. 9 is a partial sectional view taken from the plumbing circuitin FIG. 6 illustrating an exemplary dump fluid path;

[0024]FIG. 10 is a partial sectional view taken from the plumbingcircuit in FIG. 6 illustrating an exemplary drain fluid path;

[0025]FIG. 11 is a partial sectional view taken from the plumbingcircuit in FIG. 6 illustrating an exemplary supply fluid path;

[0026]FIG. 12 is a perspective exploded view, in enlarged scale, of themanifold illustrated in FIG. 3;

[0027]FIG. 13 is a partial sectional view taken from FIG. 7 illustratinga plumbing segment for accommodating a reverse hose flow configuration;and

[0028]FIG. 14 is a partial sectional view taken from FIG. 7 illustratinganother plumbing segment for accommodating a reverse hose flowconfiguration.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Referring now to FIGS. 1, 3 and 6, an exemplary embodiment of anautomotive fluid servicing apparatus, generally designated 20, of thepresent invention is illustrated. In general, such fluid servicingapparatus is incorporated in a convenient, portable wheeled cabinet 22housing a plumbing subsystem and an electrical command subsystemcooperating to drain fluid from a serviceable component, add fluid tothe serviceable component, circulate fluid between the serviceablecomponent and the apparatus, and drain collected or other stored fluidusing a single, common pump 24 and an integrated manifold assembly 26 asdirected by a service technician and controlled by aprocessor/controller 28.

[0030] Plumbing Subsystem

[0031] Turning to FIGS. 3, 6, and 12, at the heart of the plumbingsubsystem is the integrated manifold assembly 26 housing a fluid circuit30 formed in a rectangular manifold body 31 having a top side 33,opposing bottom side 35, rear side 37, front side 43, and two opposingends 45, 47. The body sides and ends have generally planar surfacescooperating to form a rectangular block measuring about six inches wideby three inches deep by three inches high and defining a number ofmanifold ports for connecting to various conduits and other hydrauliccomponents. In this exemplary embodiment, there are six conduit ports.

[0032] With particular reference to FIG. 12, an exhaust port 32, areturn port 34, a drain port 36, and a fresh fluid supply port 38 openoutwardly on the rear side 37 of the manifold body 31. While each ofthese ports are shown on the same side of the manifold body in FIG. 12,it will be appreciated that the ports may be placed at other suitablelocations on the manifold body. For instance, these same manifold portsare shown on different sides of the manifold body 31 in FIG. 6 for easeof description and clarity and may also provide suitable port locationsand is not meant to be limiting in any manner. Other suitable locationswill occur to one of ordinary skill in the art. Each manifold port isthreaded for coupling with one end of a respective conduit, hose, orother suitable tubing or piping, which are in turn connected to adesired source or destination. For ease of assembly, it is preferable tothread one portion of each hose coupling into the respective threadedport opening. The threaded coupling component is constructed to allowthe assembler to merely press the free end of the selected conduit intothe complementary coupling component threaded into the port. Suitablecouplings of this type are available from Parker Hannifin under theTrueSeal trade name.

[0033] More specifically, with reference to FIGS. 3, 6, and 12, a usedfluid conduit 39 connects between the drain port 36 and a used fluidcollection tank 40 to carry fluid therebetween. Similarly, the freshfluid supply port 38 connects via a new fluid supply conduit 41 to a newfluid tank 42. Such used fluid collection tank 40 is constructed to holda sufficient amount of used fluid to accommodate at least complete drainprocedure and preferably more. The new fluid tank 42 is typicallyconstructed to hold a sufficient volume of fresh fluid to accommodate asingle fill procedure and preferably has a greater capacity as well.This fresh fluid source 42 may be filled through a fill hole (notshown). As it is preferred that the servicing apparatus maintain aportable capability, the used and new fluid tanks are preferably mountedinside the cabinet 22 (FIG. 1) which is sized to accommodate thepreferred tank capacities. It has been found that a 24 quart capacityfor both the new and used fluid tanks accommodates most servicingprocedures.

[0034] With continued reference to FIGS. 3, 6, and 12, furtherconvenience is provided by a set of servicing hoses, 44 and 46respectively for connecting between the return port 34 and the exhaustport 32 of the servicing apparatus 20 and the influent line and effluentline of the serviceable component such as an automatic transmission asis well known to one of ordinary skill. The use of conventional adaptersis also contemplated if necessary. The connectors illustrated in FIG. 3are exemplary and not meant to be limiting in any manner as othersuitable connectors will occur to one of ordinary skill. Such connectionplaces the transmission in fluid communication with the servicingapparatus 20 as will be discussed below. The manifold body 31 furtherincludes a suction port 50 and a pressure port 52 located on the topside 53 of the manifold body (FIG. 12). These ports are also threadedfor receiving one part of corresponding suction and pressure hosecouplings 54, 56, which are connected at their opposite ends to therespective suction (inlet) and pressure (outlet) sides of the pump 24 toplace the pump in fluid communication with the manifold body 31. Suchsuction and pressure hoses also incorporate press-in connectors forconvenience of the assembler.

[0035] Still referring to FIG. 6, added to the fluid circuit 30 are anumber of pathways formed in the manifold body 31 as well as a number offlow control and filtering components for routing fluid entering andexiting the manifold between the various fluid ports 32, 34, 36, 38, 50and 52. Referring now to FIGS. 6 and 8-11, in this exemplary embodiment,there are four such pathways including a drain path, generallydesignated 57, for flow of fluid as indicated by directional arrow 58(FIGS. 6 and 10), a recirculation path, generally designated 80, forflow of fluid as indicated by directional arrow 59 (FIGS. 6 and 8), asupply path, generally designated 93, for fluid flow as indicated bydirectional arrow 61 (FIGS. 6 and 11), and a dump path, generallydesignated 95, for fluid flow as indicated by directional arrow 63(FIGS. 6 and 9).

[0036] It will be appreciated that the manifold body 31 forms a threedimensional fluid circuit and that FIGS. 6 and 8-11 are represented in atwo-dimensional layout for ease of description and are not meant to belimiting in any manner. For instance, the fluid ports in FIG. 12 areshown on one side of the manifold body while the same ports are shown onmultiple sides of the manifold body in FIG. 6. In addition, in FIG. 6,the manifold body 31 is not depicted as a rectangular block as in FIG.12. These illustrations are merely to facilitate description of thepreferred embodiment. Other suitable port locations and pathways mayoccur to one of ordinary skill and still fall within the scope of thepresent invention.

[0037] With continued reference to FIGS. 6 and 8-12, each pathway 57,80, 93, and 95 is generally tubular in transverse cross section and madeup of adjacent passage segments bored into the manifold body 31 whichare configured with straight runs meeting at right angles and compactedto minimize the size of the manifold body and further reduce hose lengthrequirements between components coupled to the manifold body and overallhose length requirements of the servicing apparatus. Some of these rightangle segments project into or out of the plane of the paper and may notbe shown in FIGS. 6, or 8-11. It will also be appreciated, whenconsidered from end to end, portions of each pathway may extend outsidethe manifold body and include couplings or connectors of flexible orrigid material connected to one or more manifold ports.

[0038] With particular reference to FIGS. 6, 10, and 12, during a drainprocedure as will be discussed below, fluid is normally directed in thedirection of arrow 58 through the drain path 57 from the return port 34to the used fluid drain port 36 which may be connected to the used fluidcollection tank 40 via conduit 39. Such passage 57 is formed by an entrybore extending into the manifold body 31, viewed into the paper in FIG.6, from the return port 34 to enter a short pre-filter segment 64 whichturns downwardly at a right angle from the entry bore, toward anaperture (not shown) in the bottom side 35 of the body aligned with afluid entrance into an in-line filter 60 to direct fluid into thefilter. The filter 60 is coupled to a hollow, threaded nipple 67projecting from the bottom side 35 of the manifold. The nipple isscrewed into an opening in the bottom side of the manifold body andfurther extends outside the body providing a connective threaded stubfor the filter 60. After exiting the manifold through the bottomaperture to enter the in-line filter 60, the drain path 57 then reentersthe manifold body through the hollow nipple and projects upwardly intothe body into a pre-drain valve segment 69. About the midpoint of thebody 31, the pre-drain valve segment terminates at an inlet of atwo-position drain/bypass solenoid valve 70 which may be screwed into athreaded valve port 65 on the top side 33 of the manifold body 31 toposition the dual outlet valve 70 in line with both the drain path 58and recirculation path 80 of the fluid circuit 30. Such valve 70includes a drain position, indicated by directional arrow 66, whichdirects fluid entering the inlet of the solenoid 70 out of a drainoutlet of the solenoid 70 and through the remainder of the drain path 58(FIGS. 6, 10) and a normally open bypass position, indicated bydirectional arrow 68, which directs fluid entering the inlet of thevalve 70 out of an alternate outlet and through a recirculation path 80(FIGS. 6, 8).

[0039] The valves described herein are preferably two-position,three-way magnetic solenoid valves, either size 8 or 10, which may beenergized to enter into a number of alternative positions. Such valvesare available from Hydac Technology Corporation in Bethlehem, Pa. Othersuitable valving arrangements for directing fluid flow to or frommultiple channels may also be used.

[0040] With continued reference to FIG. 10, the drain path 57 turns at aright angle from the longitudinal centerline of the solenoid 70 into apost-solenoid segment 72 forming the stem of a T-shaped intersection 74.Then the path is bifurcated to, in one branch, enter into a used fluidconnection branch 75 of the T-shaped intersection leading to the drainport 36 which may be connected to the used fluid collection tank 40.Fluid entering the return port 34 from the serviceable component is thusnormally directed along this drain path 57 if the drain/bypass solenoid70 is energized to the drain position 66 for collection in the usedfluid tank 40.

[0041] Referring now to FIGS. 6 and 8, when the drain/bypass valve 70 isenergized to the bypass position as indicated by directional arrow 68,the recirculation path 80 is opened and the drain path 57 is blocked.The recirculation path 80 shares the same plumbing with the drain path57 up to the drain/bypass solenoid 70 including the return port 34,pre-filter segment 64, filter 60, and pre-valve segment 69. Continuingthrough the drain/bypass solenoid valve 70, when energized to the bypassposition 68, the recirculation passage 80 projects at a right angle tothe longitudinal centerline of the solenoid to form an L-shapedrecirculation loop leading to the exhaust port 32 which may be connectedto the transmission inlet. Fluid entering the recirculation path fromthe return port 34 is directed through the solenoid 70 set in the bypassposition 68 to exhaust port 32. Such recirculation path normally servesto circulate fluid in the direction indicated by arrow 59 between theserviceable component and the servicing apparatus and through the filter60 while bypassing the pump 24, used fluid tank 40, and new fluid tank42.

[0042] With continued reference to FIG. 6, and with particular referenceto FIG. 11, the fresh fluid supply passage 93 is formed by an entry boreextending into the manifold body 31 from the new fluid supply port 38 tothen turn at a right angle forming an L-shaped pre-supply valve segment82. The segments discussed herein are preferably bored into the manifoldbody during manufacture. Such segment terminates at a two-positiondump/supply solenoid valve 84 which is also screwed into a threaded port85 on the top side 33 of the manifold body 31 to position the valve 84in line with the new fluid supply passage 93 (FIG. 11) and the dumppassage 95 (FIG. 9) in the fluid circuit 30. Such valve 84 includes anormally open supply position, indicated by directional arrow 81, whichreceives fluid withdrawn from the new fluid supply tank 42 and directsit through the remainder of the supply path 93 (FIG. 11). Thesupply/dump valve 84 also includes a dump position, indicated bydirectional arrow 83, which receives fluid being dumped from the usedfluid tank 40 and directs such fluid on through the remaining portion ofthe new fluid supply passage as well (FIG. 9).

[0043] Continuing with the new fluid passage 93, a pre-suction portsegment 86 projects at a right angle to the longitudinal centerline ofthe solenoid 84 and further includes a second right angle turn leadingto the suction port 50 (FIGS. 6 and 11). The suction side hose 54connects the suction port to the suction side of the pump 24 and apressure side hose 56 connects the pressure side of the pump 24 with thepressure port 52 at the top side 33 of the manifold body 31 to positionthe pump 24 in line with the supply path 93 (FIG. 11) and also the dumppath 95 (FIG. 9) depending on the valve 84 position. Reentering themanifold body 31 through the pressure port, the new fluid supply passage93 projects downwardly through a pre-supply filter segment 87 to lead toan aperture (not shown) on the bottom side of the manifold body 31aligned with an entry hole in a supply filter 88. The supply filter 88is also connected to the manifold body via a hollow, threaded nipple 90on the under side 35 (FIG. 12) similar to the drain filter 60connection. Exiting the filter 88 through the hollow nipple 90, the newfluid supply path 93 projects upwardly into the manifold body 31 throughan in-line one-way check valve 92 and then turns outwardly toward theback side 37 of the manifold body in an L-shaped segment 94 leading tothe exhaust port 32 which may be connected to the transmission inlet orcollection tank via servicing hose 46. The final segment 94 of the newfluid supply path 93 leading to the exhaust port 32 is common with thelast segment of the recirculation path 80.

[0044] The check valve 92 is incorporated in the supply fluid circuit 93to prevent fluid from backflowing or otherwise entering the outlet ofthe supply filter 88 from the recirculation path. This feature alsoserves to keep the pump 24 primed in use. However, it is preferable toselect a suitable pump 24 having an integrated check valve forincorporation into the servicing apparatus 20 so that the external checkvalve 92 can be omitted altogether. The supply pathway 93 normallyserves to conduct fluid in the direction of arrow 61 from the freshfluid supply 42 connected to the new fluid port 38 and direct the fluidto the exhaust port 32 and to the upstream line of the serviceablecomponent via servicing hose 46 to supply fresh fluid thereto.Alternatively, such passage 93 can be used to drain the new fluid tank42 when the servicing hose 46 is coupled to a collection tank.

[0045] Turning now to FIGS. 6 and 9, the fluid circuit 30 also includesthe used fluid dump pathway 95 for transporting fluid in the directionof arrow 63 between the drain port 36 and the exhaust port 32 fordraining fluid from the used fluid tank 40 using the common pump 24.With continued reference to FIG. 9, the dump path 95 begins with at thedrain port 36 which is normally coupled to the used fluid collectiontank 40 via the used fluid conduit 39. The dump path 95 is then formedwith a bore projecting inwardly from the drain port 36 along a straightsegment to form the first branch 75 of the T-intersection 74. The path95 bifurcates at intersection 74 to flow through to a straight pre-valvesegment 91 to one inlet of the dual inlet dump/supply solenoid valve 84which controls the flow on to the outlet bore 86 (pre-suction portsegment) leading to the suction port 50 when the valve is energized tothe dump position 83. The remaining portion of the dump path is commonto the new fluid supply path 93 as it exits the solenoid 84 ultimatelyleading to the exhaust port 32 including passage through the outlet bore86 through the suction port 50 to the inlet of the pump 24 via coupling54. The fluid is then directed through the outlet of the pump 24 throughcoupling 56 to pressure port 52 on through filter 88, check valve 92 toexhaust port 32. Such path 95 normally serves to direct fluid withdrawnfrom the used fluid collection tank 40 in the direction of arrow 63using the common pump 24 to direct used fluid through the exhaust port32. Instead of connecting the service hose 46 to the transmission,however, the free end of the service hose is typically placed in a wastefluid receptacle (not shown) for future storage so that the used fluidtank 40 may be drained.

[0046] With continued reference to FIGS. 6 and 8-11, fluid typicallyenters the return port 34 from conduit 44 connected to the downstreamport of the transmission and exits the exhaust port 32 to be directedthrough hose 46 to the upstream port of the transmission. Fluid isgenerally circulated through the fluid circuit 30 by the single,non-reversible pump 24 interposed in the supply and dump pathways 93 and95, respectively, to complete these pathways. Fluid may also becirculated by a pump associated with the serviceable component throughthe drain and recirculation paths 57 and 80, respectively. Direction ofthe fluid through the fluid circuit 30 is normally determined by therespective positions of the single inlet, dual outlet, drain/bypassvalve 70 and dual inlet, single outlet, dump/supply valve 84. Thedrain/bypass valve 70 operates to direct fluid entering the return port34 through the drain or bypass passages 57 and 80 respectively with oneside of the valve 70 in fluid communication with the return port 34 andthe second side in fluid communication with the drain port 36 andexhaust port 34. When solenoid 70 enters into the drain position 66, thebypass passage 80 is blocked off and the passage between the return port34 and the drain port 36 is open and fluid may flow in the direction ofarrow 58 (FIG. 10). On the other hand, when the valve 70 is energized tothe bypass position 68, the drain passage 57 is blocked off and thepassage between the return port 34 and the exhaust port 32 is openestablishing a bypass loop 80 wherein fluid may circulate in thedirection of the arrow 59 and wherein fluid does not circulate throughthe pump 24 (FIG. 8).

[0047] Referring to FIGS. 6, 9, and 11, connected in fluid communicationwith the supply and dump paths 93 and 95, respectively, is thedump/supply valve 84 with the outlet of the valve in fluid communicationwith the exhaust port 32 and the dual inlet in fluid communication withthe drain port 36 and new fluid supply port 38. When the valve 84 isenergized to the supply position 81, the dump passage 95 is blocked offand the passage 93 between the new fluid supply port 38 and the exhaustport 32 is open so that fluid may flow in the direction of arrow 61(FIG. 11). On the other hand, when the valve 84 is energized to the dumpposition 83, the new fluid supply passage 93 is blocked off and thepassage between the drain port 36 and the exhaust port 32 is openestablishing a passage 95 for dumping fluid in a direction indicated byarrow 63 to be collected in the used fluid tank 40 by withdrawing suchfluid with the common pump 24 (FIG. 9). Selection of these valvepositions 66, 68, 81, and 83 is directed by the controller 28 and theoperator or service technician using the electrical command system aswill now be described.

[0048] Electrical Command Subsystem

[0049] Referring now to FIGS. 1-3, and 6, the heart of the electricalcommand sub-system is the controller 28 which is a programmable circuitboard having a central processing unit (CPU) and associated memory fortransmitting control commands to the pump 24 or valves 70, 84 inaccordance with command sequences stored in the memory responsive tofeedback transmitted from a number of sensors to direct the fluidservice operations selected by a service technician. In this exemplaryembodiment, there are three such sensors.

[0050] With particular reference to FIG. 6, the controller 28 isconnected to a new fluid tank sensor 100 and a used fluid tank sensor102 through their respective electrical leads 104 and 106 to providefluid level feedback for each tank, 42 and 40, respectively. The fluidlevel sensors detect the fluid level in their respective fluid tanks andprovide this information to the controller which includes tank geometricdata and fluid density data in its memory for calculating the volume offluid in each tank. Such fluid level sensors are preferably gas sensors,available from Motorola and constructed to monitor the air pressure ineach tank. A two-port balancer system is used so that the sensors candetect outside air pressure and take into account elevation of theservicing apparatus to provide more accurate fluid level readingsthereby compensating for discrepancies between sea level readings andreadings taken at other altitudes.

[0051] The controller 28 is also in electrical communication with apressure sensor 108 through electrical lead 110. Such pressure sensor108 is threaded into an aperture 109 on the top surface of the manifoldbody 31 and is used for sensing fluid pressure in the last segment 94 ofthe fluid circuit leading to the exhaust port 32 and providing feedbackto the controller 28 and is primarily used to detect incorrect servicehose connections during the drain procedure as will be discussed below.

[0052] With continued reference to FIG. 6, the pump 24, drain/bypassvalve 70, and dump/supply valve 84 are in electrical communication withthe controller 28 via their respective electrical connectors 112, 114,and 116. Using feedback from the sensors and any additional operatorinput, the controller energizes the first and second valves 70 and 84 tothe desired positions as will be described below and further actuatesthe pump 24 to on and off states during selected servicing procedures tocirculate the fluid through the fluid circuit 30 from the desired sourceto the selected destination. Conveniently, the controller 28, a controlpanel 130, valves 70 and 84, pump 24, and sensors 100, 102, and 108 arein electrical communication with a set of battery cables 120 (FIG. 1).Thus, power may be supplied to such components capable of being poweredby a 12 volt DC source by attaching a set of battery cables 120 to thevehicle's battery. It will be appreciated that such electrically poweredcomponents could also be hardwired to an alternative power sourcelocated on the servicing apparatus itself 20 or constructed to plug intoa wall outlet.

[0053] Referring now to FIGS. 1 and 2, in this exemplary embodiment, anoperator may interface with the controller 28 via a control panel 130located on a top forward inclined surface of the cabinet 22. Suchcontrol panel is generally divided into four regions including anoptions menu listing 132 presenting the available operational options, adisplay region 134 with a plurality of LEDs and a counter display 136for indicating machine and operational status and displaying quantity ordiagnostic information, an interactive control region 138 and a powersteering exchange (PSX) pendant dock region 140 for attaching a remotecontrol for controlling power steering fluid exchange operations whichwill be described in detail below.

[0054] With continued reference to FIG. 2, the options menu listing 132positioned to the left side of the control panel 130 includes a listingof procedural options 1-9, respectfully indicated as OP1-OP9 asimprinted or otherwise provided on the face of the control panel (FIG.2). The exemplary options are as follows:

[0055] OP1 Add 1 quart of fluid;

[0056] OP2 Remove 1 quart of fluid;

[0057] OP3 Drain new fluid tank;

[0058] OP4 Drain used fluid tank;

[0059] OP5 Access new fluid volume;

[0060] OP6 Access used fluid capacity;

[0061] OP7 Auto prime the system;

[0062] OP8 New fluid sensor check; and

[0063] OP9 Used fluid sensor check.

[0064] Such exemplary options, as illustrated in FIG. 2, are accessiblevia an options menu button 142 in the control region 138 and engageableby a start exchange/options button 144 as will be described below. Thedisplay region 134 provides visual feedback to the operator as to thestatus of the fluid exchange procedures and servicing apparatus 20operation. The primary indicator is the counter display 136 whichprovides a visual display of requested information such as the servicingoption being invoked, fluid capacities, or other information in the formof alphanumeric messages.

[0065] Continuing with FIG. 2, further comprising the display region 134are a number of LED indicators divided into four columns. The firstcolumn includes a quarts LED indicator 146 and a liters LED indicator148. Such indicators indicate the system of measurement being used. Nextto the first column is a column of amount indicators including a 20quart indicator 150, a 16 quart indicator 152, a 12 quart indicator 154,and a 4 quart indicator 156. Each of these indicators provides a displayto the operator as to the amount of fluid selected by the operator foran exchange. For purposes of an automatic transmission fluid exchange,eight cylinder, full size vehicles or truck typically require a twentyquart exchange. Mid-size vehicles with 6-cylinders typically require asixteen quart fluid exchange and compact, four cylinder vehiclestypically require a twelve quart exchange. Sub-compact vehiclestypically only require a four quart exchange.

[0066] Still referring to FIG. 2, the third column in the display region134 indicates machine operation status and includes a stopped indicator158, a halted indicator 160, a running indicator 162, a completeindicator 164, a switch hoses indicator 166, and a shift to neutralindicator 168. A machine status column is the fourth column in thedisplay region 134. Such machine status column includes a new ATF lowindicator 170, a used ATF full indicator 172, an add/remove ATFindicator 174, and a new/used ATF drain indicator 176. The meaning ofthese indicators will be discussed below when the operation of theservicing apparatus is described.

[0067] Spaced below the display region 134 in the control region 138 isa first and second set of depressable buttons for initiating a varietyof functions to operate the servicing apparatus 10 (FIG. 2). Theleftmost button of the first set is a quantity button 178 for selectingthe quantity of fluid to be transferred from one location to another.Depressing this button cycles through the quantity indicators 150, 152,154, and 156. Next to the quantity button is positioned theexchange/options button 144 for initiating a fluid exchange orinitiating the option selected by the options menu button 142. A powersteering button 180 for initiating a power steering fluid exchange isnext in line followed by the option menu button 142. The options menubutton cycles through the options listed in the options menu 132 whendepressed.

[0068] The leftmost button in the right hand set of buttons is an addATF button 182 for adding automatic transmission fluid where directed bythe fluid circuit 30. Next to the add ATF button is a remove ATF button184. Selection of this button may be used to remove or drain ATF fromthe selected source. The third button is a cycle sensors button 186 forcycling the valves 70, 84 between their respective positions to clearthe valves prior to operation of the servicing apparatus 20 to ensurethe valves are in proper working order. The last button is a stop button188 for shutting the apparatus down completely in an emergency or otherdesired stop condition. Such button is preferably a larger size orotherwise stands out from the other buttons so it may be rapidly locatedby the operator. An illustrative servicing procedure using theabove-described plumbing and electrical subsystems incorporated into aservicing apparatus 20 will now be described.

[0069] Operation of the Fluid Servicing Apparatus

[0070] In the field, the manifold assembly 26 is typically securedwithin an internal compartment of the servicing apparatus 20 using asuitable threaded fasteners screwed into a pair of mounting bores 194 onthe front side 43 of the manifold body 31 (FIGS. 1 and 12) and comespreassembled. Such internal compartment is accessible via a removableservicing panel 190. The pump 24 is also preferably secured inside theservicing apparatus. The control panel 130 is also removable and mayprovide an alternative access into the compartment. Near the bottom ofthe servicing apparatus, the used and new fluid tanks 40 and 42,respectively are placed on a convenient shelf.

[0071] While the servicing apparatus 20 is typically assembled prior tooperation of the servicing apparatus 20, it will be appreciated that theintegrated manifold assembly 26 has been designed to reduce assemblytime and facilitate servicing in the field and that some connection maybe required prior to initiating servicing procedures or duringmaintenance.

[0072] Referring now to FIGS. 3, 6, and 12, starting with the basicmanifold body 31 with preformed fluid circuit 30 and built-in couplingsthreaded into the ports 32, 34, 36, 38, 50 and 52, the operator mayconnect the used fluid conduit 39 by pressing one end into the drainport 36 and the other end is inserted into or otherwise coupled to theused fluid tank 40. The supply conduit 41 is likewise coupled betweenthe supply port 38 and the new fluid tank 42. The pump 24 may then beconnected to the top side 33 of the manifold body by pressing in one endof the suction hose 54 into the suction port 50 and its opposite endinto the suction side inlet of the pump 24. Similarly, one end of thepressure side hose 56 is pressed into the pressure port 52 its other endinto the pressure side outlet of the pump 24.

[0073] With continued reference to FIG. 12, the connector nipples of thevalves, pressure sensor, and filter components may then be screwed intotheir respective threaded ports on the manifold body 31. Morespecifically, the drain/bypass valve 70 is threaded into the port 65 toplace the valve inline with the drain and bypass fluid paths, 57 and 80respectively. The inlet of the valve 70 is aligned with the terminal endof the pre-filter bore 34. The first outlet of the valve 70corresponding to position 66 is aligned with the inlet to bore 72 andthe second outlet of the drain/bypass valve 70 corresponding to position68 is aligned with the inlet to the recirculation loop 80. Likewise, thedump/supply valve 84 is screwed into threaded port 85 on the upper side33 of the manifold body to place such valve in fluid communication withthe supply and dump paths, 93 and 95 respectively. The first inlet ofvalve 84 corresponding to position 81 is aligned with the exit ofpre-valve bore 82 and the second inlet of valve 84 corresponding toposition 83 is aligned with the exit to bore 91. The outlet of valve 84is aligned with the entrance to post-valve bore 86. The nipple of thepressure switch 108 is also threaded into its respective threadedaperture 109 on the top side 33. On the bottom side 35 of the manifoldbody 31, the filters 60 and 88 are screwed onto their respective nipples67 and 90 until their respective gaskets are flush with the undersurfaceof the manifold providing a suitable seal. The entry port of the drainfilter 60 aligns with the aperture occurring at the end of the pre-drainbore 34. The entry port of the supply filter 88 aligns with the apertureoccurring at the end pre-supply filter bore 87. The filters arepreferably of the ten micron absolute variety and the threaded nipplesare preferably constructed using metric threads to inhibit a servicetechnician from bypassing the filters. Such filters also act asmaintenance indicators as fluid servicing procedures will take longer asthe filters become more and more clogged obstructing fluid flow.

[0074] Each of the electrical leads of the pump 24, valves, 70, 84, andsensor 108 along with the other DC powered components may then be placedin electrical communication with the controller 28 and battery cables120 via the wiring harness.

[0075] When the service technician is prepared to service an automobiletransmission, with reference to FIGS. 1-3, and 6, the new fluid tank 42and used fluid tank 40 may initially be empty. The servicing apparatus20 is initially prepped for servicing by filling a quantity of newtransmission fluid through a fill hole (not shown) into the new fluidtank 42. For purposes of this operational procedure, it will be assumedthat the used fluid tank 40 is initially empty and the new tank 42 hasan adequate supply of transmission fluid to perform a complete exchange.The servicing apparatus 20 is wheeled over near the transmission to beserviced. Using well known procedures, the service technician interruptsthe transmission cooling lines to expose an influent line or inlet portand an effluent line or outlet port and connects the free ends to thereturn and exhaust ports 34 and 32 of the manifold assembly 26 using theservice hoses 44 and 46 using conventional adapters if necessary.Preferably, the technician connects the effluent line of thetransmission to the return port 34 and further connects the influentline at one end to the exhaust port 32 such that the connection placesthe transmission in fluid communication with the fluid passages 57, 80,93, and 95 of the servicing apparatus 20 (FIGS. 1, 6, and 8-11). It willbe appreciated that the service hoses 44, 46 are preferably clearallowing an operator to visually check the condition of the fluid ineach hose. The default position of the drain/bypass valve 70 is thebypass position 68 blocking off the drain path 57 so that fluid flowfrom the transmission will circulate through fluid passage 80 in thedirection of arrow 59 initially when the vehicle engine is turned on toactivate the transmission pump (FIG. 8).

[0076] With continued reference to FIGS. 6 and 8, once the service hoses44, 46 are connected, the technician may then connect battery cables 120to the vehicle battery to supply power to the control panel 130,controller 28, drain/bypass valve 70, dump/supply valve 84, pump 24,sensors 100, 102, 108, all of which are preferably selected to run on a12-volt DC power supply. Using the versatile servicing apparatus 20, thetechnician may perform several servicing procedures includingcirculation and clean, automatic transmission fluid exchange by drainingand refilling the transmission in incremental steps, draining andrefilling the transmission pan, topping off fluid levels, and drainingthe new and used fluid tanks. It will be appreciated that the followingprocedures are performed using only a single common pump 24 operating inconjunction with the vehicle transmission pump for some procedures.

[0077] In the initial stage after the service hoses 44 and 46 areconnected to the return and exhaust ports 34 and 32 and transmissioncooling lines, the operator may press the cycle sensors button 186 toactuate the valves 70 and 84 through their full range of movement toclear any obstacles, debris, or other contaminants that may preventperformance.

[0078] With battery cables 120 connected, the operator may start thevehicle engine to operate the transmission pump and to pressurize fluidout of the transmission to begin circulating fluid through circulationpassage 80. This is commonly referred to as circulation mode duringwhich the pressure switch 108 in normally inactive. Depending on thetransmission pump and direction of fluid flow, used fluid from thetransmission is forced out into the recirculation passage 80 from eitherthe return port 34 or the exhaust port 32. Fluid will either flow in thedirection of arrow 59 or in a reverse direction. The fluid exits therecirculation passage 80 from the opposite port wherein fluid isentering and reenters the transmission through the associated servicinghose. The check valve 92 prevents the used fluid from entering theservicing apparatus pump 24. At this point a closed circulation loopbetween the vehicle transmission cooling lines and servicing apparatus20 is established and the running indicator 162 lights up on the controlpanel 130. It will be appreciated that the used transmission fluid isdirected through the filter 60 to remove particulate from the used fluidduring this initial procedure.

[0079] While the fluid is circulating, the operator may then select thequantity of fluid to be changed via the control board 130 connected tothe processor/controller 28 by depressing the quantity button 178 untilthe indicator 150, 152, 154, or 156 beside the desired quantityilluminates (FIG. 2). Assuming for example, a full-sized 8-cylindervehicle is being serviced, the operator selects the 20 quart quantity bytoggling the quantity button until the desired indicator lights up. Inthis instance, the 20 quart indicator 150 will light up on the controlpanel. At this point, the pump 24 is not running and fluid is only beingcirculated by the transmission pump.

[0080] Turning now to FIGS. 2, 6, 8, and 10, having selected thequantity to be exchanged, the operator presses the startexchange/options button 144 on the control panel 130 of the servicingapparatus 20, which causes several actions to occur. Initially, thecontroller 28 energizes the drain/bypass solenoid 70 to move from thebypass position 68 to the drain position 66 to block off therecirculation passage 80 and open the drain path 57. If the servicehoses have been connected properly, used fluid entering the return port34 under pressure from the transmission pump is directed through thedrain path 57, along the direction of arrow 58, through the drain port36 and used fluid conduit 39 connected thereto to be collected in theused fluid collection tank 40. Once the valve 70 is energized to thedrain position 66, the controller 28 will take a reading of the usedfluid tank sensor 102 to sense the hydrostatic pressure head therein(FIG. 6). If no fluid is sensed in the used fluid tank 40, thecontroller will also take a reading of the signal transmitted from thepressure sensor 108 to determine if any fluid is entering the exhaustport 32 and is present in segment 94. With the signal stored showing nofluid in the used fluid tank, detection of fluid entering through theexhaust port 32 into the recirculation passage 80 is indicative of animproper hose connection. If that's the case, the processor 28 actsaccordingly to alert the operator of an improper hose coupling conditionby transmitting a signal to illuminate the switch hoses indicator 166 onthe control board 130. It will be appreciated that an audible alarm maybe programmed into the controller 28 to accompany this display or any ofthe displays to further alert the operator. The operator may then turnthe vehicle engine off and manually switch the service hoses 44 and 46between the respective ports 32 and 34. Once the hoses are switched theoperator restores the servicing apparatus 20 to circulation mode asdescribed above.

[0081] On the other hand, if a no pressure signal is transmitted by thepressure switch 108 to the processor after the drain process isinitiated and no fluid is detected by the sensor 102 in the used fluidtank 40, the shift to neutral indicator 168 is illuminated. Thisoccurrence may be due to the fact that, for instance, many Chryslertransmissions pump fluid only when in neutral. If the switch hosesindicator 166 and the shift to neutral indicator 168 have not lit, thenthe hoses are connected properly and proper fluid flow has beenestablished. The transmission may then be serviced.

[0082] Assuming these error conditions do not occur, when the startbutton 144 is pressed the transmission pump will force the fluid fromthe return port 34 through the filter 60 into the drain passage 57 andthrough the solenoid valve 70 set in the drain position 66 (FIGS. 6 and10). Used fluid passing through the solenoid 70 is directed to the drainport 36 in the direction of arrow 58 and expelled into the used fluidtank 40. The level sensor 102 in the used fluid tank transmits a signalproportional to the level of the fluid entering into the used fluid tankto the processor 28 by sensing the hydrostatic pressure head of thefluid entering the used fluid tank. The pressure head data is used tocalculate the volume of fluid in the used fluid tank as the knownparameters of the tank geometry and fluid density stored in theprocessor are recalled by a volume calculation routine. In thisexemplary embodiment, once {fraction (6/10)} of a quart is collected inthe used fluid tank 40 as calculated by the processor 28, the processorwill energize the drain/bypass solenoid 70 to reenter the bypassposition 68 blocking off the drain passage 57 and forcing the fluid intothe recirculation passage 80 in the direction of the arrow 59. Otherpredetermined quantities could also be used. The processor 28 theninitiates an incremental fill mode.

[0083] Turning now to FIGS. 2, 6, and 11, to perform the incrementalfill portion of the process, the processor 28 will actuate thedump/supply solenoid 84 to cause it to assume the supply position 81 toopen the new fluid supply path 93 from the new fluid tank 42 through theservicing apparatus pump 24 to the exhaust port 32 to the transmissionvia servicing hose 46. The processor also actuates the pump 24 at thistime withdrawing fluid from the new fluid tank 42 in the direction ofarrow 61 and through the suction port 50 and suction hose 54 to thepump. Fresh fluid is then pumped out of the pump through the pressurehose 56 to pressure port 52. Such fresh fluid is directed under pressurethrough the supply filter 88 and one-way check valve 92 and, because itcan not enter the drain/bypass solenoid 70 due to incoming fluidpressure, is directed through the exhaust port 32 to the vehicle'stransmission via service hose 46. When the level in the new fluid tankis lowered an amount corresponding with {fraction (6/10)} of a quart,the level sensor 100 will transmit a signal to the processor 28 which isprogrammed to respond to shut off the internal pump 24 and then shiftthe drain/bypass solenoid 70 back into the drain position 66 to repeatthe incremental drain procedure.

[0084] This drain then fill process continues in an alternating,iterative manner as the processor 28 periodically responds to discretedrops in the level of fluid sensed by the fluid sensor 100 in the newfluid tank. When the quantity of the new fluid transferred out of thenew fluid tank equals the preselected quantity initially set by theoperator, and indicated by one of the quantity indicators 150, 152, 154,or 156, the processor will energize an exchange complete indicator 164on the control board 130 and actuate an audible signal (FIG. 2). Theprocessor 28 then shifts the drain/bypass solenoid 70 to the bypassposition 68 to switch the servicing apparatus 20 to the recirculationmode and circulates fluid through the recirculation passage 80. Asbefore, during recirculation mode, the internal pump 24 is deactivated.

[0085] In this exemplary procedure, the processor is operative to, indiscrete {fraction (6/10)} quart increments, transfer a total of 20quarts of fluid to the used fluid tank 40 and an equal volume of newfluid is withdrawn from the new fluid tank 42. Responsive to theexchange complete indicator, the operator will turn the engine off anddisconnect the service hoses 44, 46 from the servicing apparatus 20. Theoperator will then reconnect the vehicle transmission cooling loop tocomplete the servicing procedure. It will be appreciated that upon theoperator depressing the start button 144, the entire fluid exchangeprocedure will be performed automatically without further operatorintervention until he or she turns the engine off and reconnects thetransmission cooling lines, assuming no error in connection wasdetected. In addition, to prevent an overpressure condition during fluidexchange or other servicing procedures, a pressure relief valve (notshown) may be placed in communication with the fluid circuit 30 and setto relieve in response to a preselected pressure to routeoverpressurized fluid through a bypass. It will be appreciated that thealternating drain and fill exchange process takes place rapidly and anentire exchange for an eight cylinder vehicle can take place inapproximately 10-15 minutes.

[0086] Such fluid exchange will typically leave the new fluid tank 42empty or partially empty and the used fluid tank 40 partially full orcompletely full depending on the tank capacity. Should the operator thenattempt to start another servicing procedure and select an exchangequantity that exceeds the amount of fluid remaining in the new fluidtank 40, the processor 28, having taken a reading of the new fluidsensor 100, will transmit a signal to the control board 130 toilluminate the new ATF low indicator 170 to alert the operator thatthere is insufficient fluid in the new fluid tank 42 to perform theselected procedure (FIGS. 2 and 6). To refill the new fluid tank 42, theoperator may supply new fluid through its fill hole. During thisprocedure, the processor functions to illuminate the Add/Remove ATFindicator 174 alerting the operator that fluid is being added to the newfluid tank 42.

[0087] On the other hand, should the operator select an exchangequantity that would overflow the capacity of the used fluid tank 40, theprocessor, having taken a reading of the used fluid sensor 102, willtransmit a signal to the control board 130 to illuminate the used AFTfull indicator 172 alerting the operator to drain the used fluid tankbefore proceeding. Conveniently, the fluid circuit 30 and common pump 24enable such draining or dumping of the used fluid tank 40 without theassistance of a dedicated drain pump.

[0088] Referring now to FIGS. 1, 2, and 9, to initiate the used fluiddump procedure, the operator will connect one end of the servicingconduit 46 to the exhaust port 32 and place the free end of theservicing conduit into a fluid waste tank (not shown). The operator willthen depress the options button 142 on the control panel 130 to scrollthrough the options menu (OP1-OP9) until the desired option is displayedin the counter display 136. In this scenario, the OP4 option code wouldbe displayed in the counter display 136 indicating that the operator haselected to drain the used fluid tank. Conveniently, the operator mayrefer to the option menu 132 imprinted on the left side of control panel130 to determine the procedure associated with the option code. Next,the operator may engage the start button 144 to begin the used fluiddumping procedure. In response to the operator's command, the controller28 energizes the dump/supply valve 84 to its dump position 83 to openthe dump passage 95 and then actuates the pump 24 to begin drawing fluidfrom the used fluid tank 40 through the open dump passage in thedirection of arrow 63. The fluid is expelled through the exhaust port 32through the servicing conduit 46 and into the storage receptacle. Oncethe controller 28 detects the used fluid tank is at a predeterminedbottom operating level via the used fluid level sensor 102, thecontroller will shut the pump 24 off and terminate the procedure. Bypressing the start button 144 for five seconds the operator can effectdraining of the used fluid collection tank 40 until the stop button 188is pressed. An audible alarm sounds when the used fluid tank level isempty as sensed by the used fluid sensor 102 and illumination of thecomplete indicator 164 on the control panel 130 alerts the operator thatthe dump procedure is completed. It will be appreciated that theplumbing circuit of the exemplary embodiment enables draining of theused fluid tank without the necessity of inverting the tank upside downto drain from its top end or incorporating an extra dedicated drain pumpto draw the used fluid from the used fluid tank and direct it to a wastefluid collection receptacle.

[0089] In a similar manner, the new fluid tank 42 may also be drainedcompletely as desired. Referring now to FIGS. 1, 2, 6, and 11, asdescribed for the used fluid tank 40 dumping procedure, one end of theservicing conduit 46 may be connected to the exhaust port 32 and itsfree end placed into a new fluid storage receptacle (not shown). In thisscenario, the operator may toggle the options button 142 until OP3 isdisplayed in the display counter 136. Activation of the exchange/optionsbutton 144 will cause, the controller 28 to shift the dump/supply valve84 to its supply position 81. The pump 24 is also actuated and fluid isdrawn from the new fluid tank 42 along the supply passage 93 in thedirection of arrow 61 to be expelled through the exhaust port 32. Theexpelled fluid is transferred through the servicing hose 46 to the newfluid receptacle for storage. The processor 28 is responsive to thesensor 100, sensing that the fluid level in the new fluid tank hasfallen to a predetermined bottom operating level to shut the pump 24 offand terminate the drain new fluid procedure. The operator may then pressand hold the start button 144 for five seconds to initiate a full drainof the new fluid tank 42 until the stop button 188 is pressed. Anaudible alarm sounds when the new fluid tank level is empty as sensed bythe new fluid sensor 100 and the complete indicator 164 is illuminatedby the processor on the control board 130 (FIG. 2).

[0090] Turning now to FIGS. 2 and 6, it will be appreciated that theoperator may check the new fluid volume and used fluid capacity ascalculated by the controller 28. To display the new fluid volume in thenew fluid tank 42, the operator may depress the options button 142 andscroll through the options menu until OP5 is displayed in the counterdisplay 136. The operator may then simply depress the startexchange/options button 144 and the new fluid level sensor 100 sends asignal to the controller 28 which processes the signal and displays thenew fluid level in the counter display 136 in the measurement selected(quarts or liters). Likewise, to check the remaining capacity in theused fluid tank 40, the operator may select OP6 using the options menubutton 142 and then depress the start button 144. The used fluid levelsensor 102 will detect the used fluid level in the used fluid tank 40and transmit the corresponding signal to the controller 28. The signalis processed and the remaining capacity is calculated and displayed onthe counter display 136. These features may be used by the operatorprior to initiating a servicing sequence or in response to an indicatorlight from the control panel concerning fluid levels or any other timeas selected by the operator.

[0091] With continued reference to FIGS. 1 and 6, prior to beginning aservicing sequence, the operator may desire to auto prime the servicingapparatus 20. This feature is used to purge air out of the system.Preferably, at least six quarts of new fluid must be present in the newfluid tank 42 to initiate this procedure. After ensuring the properfluid level in the new fluid tank, the operator connects one end of eachservicing hose 44 and 46 to the respective return and exhaust ports 34,32 and connects the free ends of the hoses together with a priming hose(not shown) to complete the circulation loop. The operator then selectsOP7 by toggling the options menu button 142 and then depresses the startbutton 144. During the auto prime procedure, the controller 28 willactuate the pump 24 to begin drawing fluid from the new fluid tank 42through the supply path 93 and expelling fluid through the exhaust port32. The expelled fluid is transferred through the servicing hoses 46 and44 and interconnecting priming hose (not shown) to the return port 34.During this fluid transfer, the controller 28 cycles the drain/bypassvalve 70 between first and second positions 66 and 68, respectively tobuild up bursts of pressure to purge unwanted air in the servicingapparatus 20. Once three quarts of fluid have been transferred to theused fluid tank 40, the procedure is terminated by the controller 28.Such procedure is typically initiated prior to a fluid exchange.

[0092] Referring now to FIG. 2 and 6, another set of features engageablethrough the control panel 130 include filling the and drainingtransmission pan without removing the pan. In order to perform a quickfill of the transmission pan, the servicing hose 46 is connected betweenthe exhaust port 32 and an interrupted influent cooling line or fillingport of the transmission. The operator may then select OP1 using theoptions menu button 142 and depress the start button 144 to initiate theprocess. The controller 28 energizes the dump/supply valve 84 to thesupply position 81 and actuates the pump 24 to transfer fluid from thenew fluid tank 42 in a one quart increment to the transmission (FIG.11).

[0093] To drain the transmission pan, the servicing hose 44 is connectedbetween the return port 34 and an interrupted effluent transmissioncooling line or outlet. OP2 is selected by the operator using theoptions menu button 142 and the operator may then depress the startbutton 144. Drain/bypass valve 70 is energized by the controller 28 todrain position 66 establishing an open drain path 57 (FIG. 10). Theoperator may then turn the vehicle ignition on to start the transmissionpump forcing fluid out through the transmission effluent line and intothe return port 34 through the drain path 57, in the direction indicatedby arrow 58, to be collected in the used fluid tank 40. Once a quart hasbeen removed as detected by the used fluid level sensor 102 anddetermined by the processor 28, the complete indicator 164 on thecontrol board illuminates alerting the operator to terminate theprocedure.

[0094] Two other options may be used to check the new and used fluidsensors 100 and 102, respectively. To access the new fluid sensor check,the operator may access the options menu 132 by depressing the optionsmenu button 142 until OP8 is displayed in the counter display 136. Theoperator then depresses the start exchange/options button 144. The newfluid level sensor 100 will transmit a signal to the controller 28corresponding to the fluid volume in the new fluid tank 42. An absolutereading, which is typically between 300 and 4096 fluid units, will bedisplayed on the display counter 136. The start button 144 is thendepressed again to zero the absolute reading. A measured quantity of newfluid such as one quart is poured into the new fluid tank 42 through thefill hole. A new reading corresponding to the amount of fluid pouredinto the new fluid tank is measured by the processor 28 via the newfluid sensor 102 and displayed on the counter display 136. For example,if one quart is added, the counter display 136 should read 78 fluidunits. Any other reading indicates the sensor may need to be replaced orrecalibrated.

[0095] A similar procedure may be used to check the used fluid levelsensor 102. In this scenario, the operator selects OP9 in the displaycounter 136 using the options menu button 142 and depresses the startbutton 144. An absolute reading is displayed and then zeroed bydepressing the start button 144 again. A known quantity of fluid ispoured into the used fluid tank 40 which is measured by the used fluidlevel sensor 102 and displayed on the display counter 102. If thequantity displayed does not correspond to the amount poured in then theoperator is alerted that the used fluid sensor may need to be replacedor recalibrated.

[0096] Another convenient feature programmed into the controller 28 isthe totalizer. Such feature keeps track of the number of fluid unitspassing through the servicing apparatus 20. The total amount may bedisplayed in the display counter 136. As the display counter may onlydisplay a certain number of digits, a separate rollover counter isdisplayed indicating how many times the counter has reached itsnumerical limit. For example, if two digits were dedicated to thetotalizer display, a display reading of “2” is displayed initially andis followed by a “78”. Such display indicates the servicing apparatushas circulated 278 quarts of fluid. Advantageously, this feature enablesthe operator to develop a maintenance or replacement plan for theservicing apparatus 20 and its components. This feature is accessiblethrough depressing the stop button 188 for approximately 5 seconds.

[0097] The capability for smaller increment level adjustments is alsoconveniently built into the servicing apparatus 20. For example, ifduring an exchange operation, the operator elects to top off thetransmission fluid level with the hose 46 connected between the exhaustport 32 and the transmission influent line or inlet, the operator maydepress the add ATF button 182 on the control panel 130 (FIG. 2). Inresponse, the controller 28 commands the dump/supply valve 84 to thesupply position 81 and further commands the pump 24 to actuate such thata predetermined amount of new fluid is transferred along the supply pathto the transmission (FIG. 11). It has been found that about {fraction(2/10)} of a quart is a sufficient amount for such incremental fluidtransfers although it will be appreciated that other suitable levels maybe used. Once the predetermined amount has been removed from the newfluid tank 42, the controller 28 shuts the pump 24 off to terminate thetransfer.

[0098] To withdraw a relatively small increment of used fluid from thetransmission, the operator selects the remove ATF button 184 on thecontrol panel 130 while the vehicle transmission is running and the hose44 is connected between the return port 34 and the transmission effluentline or outlet (FIGS. 2 and 10). The controller 28 will then command thedrain/bypass valve 70 to assume the drain position 66 such that usedfluid is transferred from the transmission under the pressure of thetransmission pump through the return port 34 to the used fluid tank 40in the direction of arrow 58 through the drain path 57 upon turning thevehicle engine on. Once a {fraction (2/10)} of a quart or otherpredetermined increment is added to the used fluid tank 40, thecontroller 28 actuates the valve 70 to bypass position 68 to direct thefluid through the bypass/recirculation pathway 80.

[0099] It will be appreciated that the present embodiment is designed todetect reverse flow without harming the apparatus, transmission, oroperator, and to prevent fluid exchange until the fluid flow isconducted in a direction wherein the effluent flow from the transmissionpasses into the return port 34 and the influent flow to the transmissioncomes from the exhaust port 32. While such features have been providedin the servicing apparatus 20 to minimize operator intervention andfacilitate maintenance of the servicing apparatus and alert the operatorto error conditions, as discussed above, it is contemplated that anoperator may on occasion inadvertently couple the service hoses 44 and46 between the transmission and servicing apparatus 20 incorrectly thuscreating a reverse fluid circulation condition. While this may beadequately handled as described above with an alert to the operator,other ways of handling this condition are also contemplated by thepresent invention.

[0100] Cross Flow Operation

[0101] As discussed above, it is foreseeable that an operator mayinadvertently connect the hoses 44 and 46 improperly and upon initiatingan exchange procedure, a switch hoses indicator 166 would illuminate onthe control board 130 to alert the operator to the error conditionindicating that fluid is flowing in a direction opposite to direction ofarrow 59. The operator may then turn the engine off and manually switchthe hoses 44 and 46 by disconnecting and reconnecting them to the properreturn and exhaust ports 34 and 32. The technician may then restart thevehicle and initiate the fluid exchange as described above.

[0102] Referring now to FIG. 7, wherein like components are likenumbered, a second exemplary embodiment of the present inventionincludes an alternative manifold body 231 for avoiding the necessity ofmanually switching the hoses 44 and 46. In general, this alternativeembodiment is constructed the manner as the first manifold body 31described above with the exception that an alternative valve 270 hasbeen substituted in place of the drain/bypass valve 70 of the firstembodiment. Such alternative valve 270 is preferably a 3-position,4-way, magnetic solenoid valve with cross flow capabilities. Thecrossflow valve 270 includes a normal fluid exchange position, indicatedby directional arrows 272, a bypass position, indicated by a U-shapedsymbol 274, and a cross flow fluid exchange position, indicated bydirectional arrows 276.

[0103] With continued reference to FIG. 7, when energized to the normalfluid exchange position 272 by the processor 28, used fluid entering thereturn port 34 is transferred to the used fluid tank 40 and new fluidwithdrawn from the new fluid tank 42 may be transferred to the exhaustport 32 in a manner similar to that described above in the firstembodiment. This is effectively the same as the fluid exchange flowalong the drain path 57 and supply path 93 as in the first embodiment asillustrated in FIGS. 6, 9, and 11.

[0104] If, however, the controller 28 energizes the alternative valve270 to the bypass position 274, the servicing apparatus 20 is placed ina bypass/recirculation mode similar to the recirculation path 80illustrated in FIG. 8. Thus fluid may be circulated between thetransmission and servicing apparatus as described above with servicehoses 44 and 46 connected between the return port 34, exhaust port 32and transmission influent and effluent lines. Fluid being circulatedduring this mode may circulate in either direction as determined by theflow from the transmission.

[0105] Referring now to FIGS. 2, 7, and 13-14, in those instances wherethe operator has incorrectly coupled the servicing hoses 44 and 46 tothe servicing apparatus 20 so that used fluid enters through the exhaustport 32 instead of the return port 34 and the start button 144 on thecontrol panel 130 is depressed, the controller 28, upon receiving asignal that no fluid is entering the used fluid tank 40 and detectingfluid pressure via the pressure sensor 108, reacts accordingly byenergizing the crossflow valve 270 to assume its cross flow position276. As shown in FIGS. 7 and 14, in this position, it will beappreciated that fluid entering through the exhaust port 32 will bedirected through the solenoid 270 to cross over to the drain path,generally designated 257, to flow in the direction indicated by arrow258, where the used fluid may then be expelled through drain port 36 tobe collected in the used fluid tank 40. In such scenario, service hose46 is an inhose and port 32 is an inflow port. Likewise, new fluidsupplied from the pump 24 in the supply path, generally designated 293,to flow in the direction indicated by arrow 261, and passing throughfilter 88 flows through the check valve 92 and cross over valve 270 andis directed to the return port 34 which in this scenario operates as anoutflow port and hose 44 is an outhose (FIGS. 7 and 13). With thesolenoid 270 configured in the cross position 276, normal transmissionfluid exchange procedures may be performed as described for the firstembodiment above. Thus, it will be appreciated that such valve 270enables the operator to connect the hoses 44 and 46 without concern asto the flow direction as determined by the transmission configuration.Once the controller 28 establishes the proper valve position 272, 274,or 276, all servicing procedures may be performed as described above forthe first embodiment.

[0106] While the above described embodiments serve particularly well inservicing automatic transmissions, the present invention furthercontemplates servicing other automobile fluid systems as well andprovides such convenience in a single portable wheeled apparatus.

[0107] Power Steering Fluid Servicing

[0108] For example, referring now to FIGS. 4-5, another embodiment ofthe present invention will now be described. When an automobile is takenin for transmission servicing, it is typically necessary and convenientto exchange the power steering fluid at the same time. Advantageously,the present invention may incorporate additional plumbing to facilitatesuch a power steering fluid exchange. FIG. 4 illustrates the additionalplumbing for adding fluid to the power steering fluid reservoir (notshown). Such new power steering fluid (PSX) circuit, generallydesignated 200, is a conduit or servicing hose with several inlinecomponents including a new power steering fluid tank 204 preferablyhaving at least a two quart capacity, a new fluid filter 206, and a newpower steering fluid pump 208 in fluid communication with one anotherand terminating at one end in a coupling 210 or free end for insertinginto the open fill hole of the power steering reservoir. An inline ballvalve 223 is provided proximate the hose end to open and close the PSXsupply circuit 220 and prevent residual fluid in the conduit fromleaking out inadvertently.

[0109] Turning now to FIG. 5, for removing fluid from the power steeringreservoir, a PSX drain circuit, generally designated 220 is alsoprovided. Such drain circuit is a servicing hose or conduit with severalinline components including a drain pump 222, a used PSX filter 224 andterminating at one end in a coupling 222 or free end for insertion intothe power steering fluid reservoir. An inline ball valve 225 is providedfor opening and closing the drain circuit for similar purposes to ballvalve 223. The other end of the PSX drain circuit is convenientlycoupled to the used fluid tank 28 (FIG. 6) so that one common tank mayaccept either used transmission fluid or used PSX fluid. Such PSX supplypump 208 and PSX drain pump 222 are connected to the controller 28 (FIG.6) which may actuate either pump. The PSX supply and drain pumps mayalso be powered by the battery cable 120 connection to a 12 volt DCpower source such as the vehicle battery.

[0110] Referring now to FIG. 2, the operator may depress the powersteering button 180 located on the control panel 130 to initiate a powersteering fluid exchange by setting the servicing apparatus 20 in PSXmode. Alternatively, the power steering exchange may be performed usinga remote pendant 230 having an “ADD” button 221 and a “DRAIN” button 227(FIG. 1). Such pendant may be directly connected to the controller 28via suitable electrical cabling or communicate with the controller usingwireless technology including radio frequency or infrared communication.It is further contemplated that the ball valves 223, 225 may be coupledto the pendant 230 and remotely actuatable. Conveniently, when not inuse, the pendant is releasably retained on the control panel using aremovable magnetic holder 229 placed on the control board 130 in thependant dock region 140 (FIGS. 1 and 2).

[0111] In operation, and with particular attention to FIGS. 1-2, 4 and5, to exchange the power steering fluid in the power steering fluidreservoir, the following exemplary procedure may be used. The apparatus20 is initially wheeled over near the vehicle and the operator attachesthe battery cables 120 to the vehicle battery providing power to theservicing apparatus 20 and drain and supply pumps 208, 222. The operatormay then depress the power steering button 180 to set the servicingapparatus 20 into power steering fluid exchange mode. “PS” will displayin the display counter 136 on the control board 130 to indicate powersteering mode is engaged. The cap of the power steering reservoir, andany screen, is removed. The operator may then start the vehicle ignitionto start the engine running. The PSX drain coupling 222, which may be anopen hose end is placed inside the power steering reservoir as is thesupply coupling 210, also an open hose end. The hoses are preferablyequal in length and are disposed near the bottom of the power steeringfluid reservoir and are maintained at all times beneath the top fluidlevel in the fluid reservoir. Each ball valve 223, 225, of therespective supply and drain circuits 200, 220 are opened fully.Conveniently, the remote pendant 230 may be removed from its holder 229and held by the operator to extend operator mobility. The magneticholder may then be used to hold the hoses of the drain and supplyconduits in place to prevent the hoses from tangling. With the ballvalves 223, 225 open, the operator depresses the Add and Drain buttons221, 227 on the pendant 230 alternately to repeatedly drain and fill thereservoir while observing the fluid level in power steering fluidreservoir (FIGS. 1, and 4-5). This flushes the old fluid out of thereservoir. With the engine still running, the operator turns thesteering wheel fully to the left and right and then back to the centerand then checks the fluid color in the reservoir. Using the pendantallows the operator to move between the steering wheel and fluidreservoir. The alternating drain and fill step and wheel turning stepare repeated until a satisfactory fluid color is observed. During thisprocess, the processor 28 monitors the used fluid tank 40 level via theused fluid sensor 102. If a used fluid tank overflow condition isanticipated, the processor 28 disables the drain button 227 on thependant, illuminates the used fluid full indicator 172, and sounds analarm.

[0112] Once the operator notes the desired fluid color indicating theexchange is complete, the operator may depress the ADD button 221 on thependant to top off the power steering fluid reservoir. Alternatively,the operator may observes bubbles in the power steering fluid reservoirindicating that the new fluid supply has been exhausted. The operatormay then turn off the engine off and replace the cap and screen, if any,on the power steering fluid reservoir. Depressing the power steeringbutton 180 again resets the servicing apparatus to automatictransmission fluid exchange mode. It is apparent that the remote pumpactuator conveniently allows the operator to move back and forth betweenthe vehicle steering wheel and the power steering fluid reservoir asnecessary.

[0113] It will be appreciated that system described herein is capable ofperforming a number of operations including draining the used ATF fluidfrom the transmission, adding new ATF fluid to the transmission,draining the used fluid tank, draining the new ATF tank, using a singlecommon pump coupled to a fluid circuit provided by an integratedmanifold assembly constructed to minimize assembly time. Additionalplumbing features may also be introduced to perform cross flowsituations as well as service the power steering reservoir with aservicing apparatus incorporating a minimal amount of components.

[0114] The common pump 24 is preferably a one-way 130 psi pump availablefrom Shur-Flo. The power steering drain and fill pumps 208, 220 are alsoavailable from Shur-Flo and of a 45 psi variety. Other suitable pumpvarieties may also be used. The pressure switch is preferably set toabout 6 psi and is available from the Nason Company.

[0115] It will be appreciated that the drain path 58 (FIG. 10) betweenthe return port 34 and drain port 36 is formed almost entirely withinthe manifold body as is the recirculation path 59 (FIG. 8) between thereturn port 34 and exhaust port 32. Such paths only exit the manifoldbody to enter filter 60. In addition, much of the dump and supply path61, 63, respectively, lengths are formed within the manifold body 31 aswell with only a relatively short segment extending outside the manifoldbody to pass through the pump 24 or filter 88. Incorporation of a numberof right angles in the pathways is formed using three longitudinallyprojecting bores which are perpendicular from the passages projectingfrom the ports on the rear and top surfaces of the manifold body 31. Thebores ends are plugged during manufacture 192. By forming most of thefluid circuit within the manifold body, the hose length requirements aresignificantly reduced and the drawbacks of using hose segments such asthose caused by high temperatures are effectively removed as well.

[0116] While a rigid manifold body having a preformed fluid circuit hasbeen described in these exemplary embodiments, it is contemplated thatsuch manifold body could also be a hollow or a partially hollow shellincorporating flexible or rigid conduits internally between the variousports.

[0117] While the present invention has been described herein in terms ofa number of preferred embodiments for performing fluid servicingprocedures on a vehicle, various changes and improvements may also bemade to the invention without departing from the scope thereof.

What is claimed is:
 1. An apparatus for servicing an automobile fluidcontaining subsystem having a fluid reservoir with a subsystem pump anda subsystem inlet and a subsystem outlet, said apparatus comprising: amanifold defining an exhaust port for coupling to said subsystem inlet,a return port for coupling to said subsystem outlet, a fresh fluid port,and a used fluid port; a fluid transfer circuit at least partiallyformed within said manifold between said ports; a drain/bypass valvehaving a fluid receiving inlet in communication with said return portand a multi-directional outlet, said drain/bypass valve beingselectively operable to place said return port in fluid communicationwith either said exhaust port or said used fluid port; a fresh fluidsource coupled to said fresh fluid port; a common pump coupled to saidmanifold and interposed between said new and used fluid ports and saidexhaust port for pumping a fluid from either of said fluid ports to saidexhaust port; a dump/supply valve having a fluid expelling outlet incommunication with said common pump and a multi-directional inlet, saiddump/supply valve being selectively operable to place either of saidused or new fluid ports in fluid communication with said exhaust port;and whereby, said exhaust port may be coupled to said subsystem inletand said return port may be coupled to said subsystem outlet, then saidsubsystem pump activated and said common pump selectively operated todirect at least one fluid through said fluid transfer circuit betweenports as determined by the selective operation of at least one of saidvalves.
 2. The apparatus as set forth in claim 1 wherein: said fluidtransfer circuit includes a drain path for directing fluid entering saidreturn port to said used fluid port, a bypass path for directing fluidentering said return port to said exhaust port, a supply path fordirecting fluid entering said fresh fluid port to said exhaust port, anda dump path for directing fluid entering said used fluid port to saidexhaust port.
 3. The apparatus as set forth in claim 2 wherein: saidmanifold is constructed to cause said drain and bypass paths to divergeat a point in said fluid transfer circuit downstream from said returnport.
 4. The apparatus as set forth in claim 2 wherein: said manifold isconstructed to cause said supply and dump paths to converge at a pointin said fluid transfer circuit upstream of said exhaust port.
 5. Theapparatus as set forth in claim 3 wherein: said drain/bypass valve isinserted into said fluid transfer circuit at said point of divergenceand is selectively operable between a drain position and a bypassposition.
 6. The apparatus as set forth in claim 4 wherein: saiddump/supply valve is inserted into said fluid transfer circuit at saidpoint of convergence and is selectively operable between a supplyposition and a dump position.
 7. The apparatus as set forth in claim 2wherein: said paths are formed of adjacent linear segments within saidmanifold.
 8. The apparatus as set forth in claim 1 wherein: saidmanifold includes a suction port downstream of said fluid expellingoutlet of said dump/supply valve and a pressure port upstream of saidexhaust port in said fluid transfer circuit; and said common pumpincludes a suction side coupled to said suction port via a suction hoseand a pressure side coupled to said pressure port via a pressure hose.9. The apparatus as set forth in claim 1 further including: a used fluidreceptacle coupled to said used fluid port.
 10. The apparatus as setforth in claim 9 wherein: said used fluid receptacle includes a usedfluid sensor for providing a signal proportional to a used fluid levelin said used fluid receptacle; and said fresh fluid source includes anew fluid sensor for providing a signal proportional to a fresh fluidlevel in said fresh fluid source.
 11. The apparatus as set forth inclaim 1 further including: a fluid transfer segment leading to saidsecond port and including a pressure sensor in communication with saidfluid transfer segment for sensing fluid pressure in said segment. 12.The apparatus as set forth in claim 1 further including: a drain sidefilter connected to said manifold and interposed between said returnport and said drain/bypass valve.
 13. The apparatus as set forth inclaim 1 further including: a supply side filter connected to saidmanifold and interposed between said pump and said exhaust port.
 14. Theapparatus as set forth in claim 1 further including: a first filterconnected to said manifold and interposed between said return port andsaid drain/bypass valve; and a second filter connected to said manifoldand interposed between said pump and said exhaust port.
 15. Theapparatus as set forth in claim 14 wherein: said first and secondfilters are connected to said manifold by first and second threaded,hollow, nipples.
 16. The apparatus as set forth in claim 1 wherein:wherein said first and second valves are 2-position, 3-way solenoidvalves.
 17. The apparatus as set forth in claim 1 wherein: said manifoldis constructed of a rigid material and said fluid transfer circuit isformed of passages with rigid walls.
 18. A manifold assembly for use inconjunction with a fluid exchanger including a used fluid receptacle, anew fluid tank, said manifold assembly comprising: a fluid circuitincluding a drain path for directing fluid entering a return port to aused fluid port, a bypass path for directing fluid entering said returnport to an exhaust port, a supply path for directing fluid entering afresh fluid supply port to said exhaust port, and a dump path fordirecting fluid entering said used fluid port to said exhaust port, saidsupply and dump paths including a common passage wherein said used fluidport may be connected to said used fluid receptacle and said supply portmay be connected to said new fluid tank; a pump disposed inline withsaid common passage for pumping fluid through said supply and drainpaths; a valving component selectively operable to divert fluid enteringsaid return port between said used fluid port and said exhaust port andto direct fluid from either said supply port or said drain port to saidexhaust port; and a rigid block body housing at least a portion of saidfluid circuit and formed on its outer surface with said ports.
 19. Themanifold assembly as set forth in claim 18 further including: a drainfilter interposed in said fluid circuit between said return port andsaid valving component.
 20. The manifold assembly as set forth in claim18 further including: a supply side filter interposed in said fluidcircuit between said pump and said exhaust port.
 21. The manifoldassembly as set forth in claim 18 further including: a drain filterinterposed in said fluid circuit between said return port and saidvalving component; and a supply side filter interposed in said fluidcircuit between said pump and said exhaust port.
 22. The manifoldassembly as set forth in claim 21 wherein: each of said filters isthreadably attached to said rigid block body via a threaded, hollownipple.
 23. The manifold assembly as set forth in claim 18 wherein: saidvalving component includes first and second valves threadably coupled tosaid rigid block body with said first valve being selectively operableto divert fluid entering said return port between said used port andsaid exhaust port and said second valve being selectively operable todirect fluid from either said supply port or said drain port to saidexhaust port.
 24. The manifold assembly as set forth in claim 18 furtherincluding: a pressure switch coupled to said rigid block body anddisposed in fluid communication with said bypass path and responsive tofluid pressure therein.
 25. The manifold assembly as set forth in claim18 wherein: said paths are formed of adjacent linear segments withinsaid rigid block body.
 26. The manifold assembly as set forth in claim18 wherein: said rigid block body is formed of aluminum.
 27. Themanifold assembly as set forth in claim 18 wherein: said rigid blockbody is formed of a transparent material.
 28. The manifold assembly asset forth in claim 18 wherein: said rigid block body is formed of apolymeric material.
 29. A manifold assembly for use in conjunction witha servicing apparatus having a used fluid receptacle, a fresh fluidsource, and first and second hoses connected to an inlet and outlet of avehicle subsystem having a fluid reservoir, said assembly comprising: arigid block body defining at least a portion of a fluid circuit betweena return port constructed to be connected to said first hose, an exhaustport constructed to be connected to said second hose, a used fluid portconstructed to be connected via a drain hose to said used fluidreceptacle, and a fresh fluid supply port constructed to be connectedvia a supply hose to said fresh fluid source, a suction port, and apressure port, said fluid circuit including a drain path between saidreturn port said used fluid port, a bypass path between said return portand said exhaust port, a supply path between said fresh fluid supplyport and said exhaust port, and a dump path between said used fluid portand said exhaust port, said supply and dump paths including a commonpassage; a first valve threadably received in said body disposing saidfirst valve in communication with said drain and bypass paths, saidfirst valve being selectively operable to open and close said drain orbypass paths; a second valve threadably received in said body disposingsaid second valve in communication with said supply and dump paths, saidsecond valve being selectively operable to open and close said supplyand dump paths; and a pump inline with said common passage and having afirst conduit coupled to said suction port and a second conduit coupledto said pressure port.
 30. The manifold assembly as set forth in claim29 wherein: said hoses and said conduits may be pressed into theirrespective said ports and releasably retained thereto.
 31. A manifoldassembly for use in conjunction with a servicing apparatus including aused fluid receptacle, a fresh fluid source, a pump, an inlet servicinghose, and an outlet servicing hose, said assembly comprising: a fluidcircuit defining means including a rigid block manifold having a returnport for coupling to said inlet servicing hose, an exhaust port forcoupling to said outlet servicing hose, a fresh fluid port for couplingto said fresh fluid source, a used fluid port for coupling to said usedfluid receptacle, and a fluid transfer circuit at least partially formedwithin said manifold between said ports; a first flow diverting meansfor selectively diverting fluid entering said return port to either saidexhaust port or said used fluid port; a second flow diverting means forselectively diverting fluid from said used fluid port or said freshfluid port to said exhaust port; and a pumping means interposed betweensaid fluid ports and said exhaust port for pumping a fluid from eitherof said fluid ports to said exhaust port.
 32. A manifold assembly foruse in conjunction with a fluid servicing apparatus having used and newfluid tanks and a pair of service hoses comprising: a manifold bodydefining first and second pathways for fluid transfer therethrough andfurther defining at least one filter receiving aperture and at least onevalve receiving aperture; a return port on said manifold body adapted tobe coupled to an end of one of said service hoses; an exhaust port onsaid manifold body adapted to be coupled to an end of an other of saidservice hoses; a used fluid port on said manifold body in fluidcommunication with said return port via said first pathway and adaptedto be coupled to said used fluid tank; a new fluid port on said manifoldbody in fluid communication with said exhaust port via said secondpathway and adapted to be coupled to said new fluid tank; a filtercoupled to said manifold in said filter receiving aperture to filterfluid passing through at least one of said pathways; and a valve coupledto said manifold in said valve receiving aperture and selectivelyoperable to divert fluid between pathways.
 33. A method of assembling amanifold apparatus for use in conjunction with a servicing apparatusincluding a cabinet carrying a used fluid receptacle, a fresh fluidsource, a pumping device, and including an outlet hose and an inlethose, said method comprising: providing a rigid manifold body includingat least one filter port, at least one valve port, an in-hose port, anout-hose port, a used fluid port, and a new fluid port, a suction portand a pressure port, said body including a plurality of passagesconstructed to place each of said ports in fluid communication with atleast one other of said ports, when in use; coupling a filter to saidfilter port; coupling a first valve to said first valve port; mountingsaid body to said cabinet; coupling said in-hose port to said inlethose; coupling said out-hose port to said outlet hose; coupling saidused fluid port to said used fluid receptacle; coupling said new fluidport to said fresh fluid source; and coupling said pump to said suctionand pressure ports.
 34. The method as set forth in claim 33 furthercomprising: providing at least one conduit having a first end forcoupling a port to a hose, receptacle, or source and having a secondfree end; pressing said free end into a selected port to releasablyretain said free end thereto.